The second Sentinel-1 satellite - Sentinel-1B - was launched today to provide more 'radar vision' for Europe's environmental Copernicus programme.
Sentinel-1B lifted off on a Soyuz rocket from Europe's Spaceport in Kourou, French Guiana, at 21:02 GMT (23:02 CEST), separating from the rocket's Fregat upper stage 23 minutes 35 seconds later.
Sentinel-1B joins its identical twin, Sentinel-1A, in orbit to deliver information for numerous services, from monitoring ice in polar seas to tracking land subsidence, and for responding to disasters such as floods.
"The launch of Sentinel-1B marks another important milestone as this is the first constellation we have realised for Copernicus," said ESA's Director General Jan Woerner.
"Orbiting 180° apart, the two satellites optimise coverage and data delivery for services that are making a step change in the way our environment is managed."
Both satellites carry an advanced radar that images Earth's surface through cloud and rain regardless of whether it is day or night.